integral density

例句：

1. 1.The density of the material is crucial for its strength and durability.
   材料的密度对其强度和耐用性至关重要。
2. 2. In mathematics, integral density refers to the total mass of a system divided by its volume.
   在数学中，积分密度是指系统的质量除以体积。
3. 3. The engineer calculated the integral density of the materials used in the construction.
   工程师计算了用于建筑的材料的积分密度。